Frugal Radio: Listening in to Live Theatre Wireless Microphones with an SDR

In one of his latest videos, Rob from the Frugal Radio YouTube channel gives us an interesting alternative way to enjoy a theatre show by demonstrating what he heard on his Airspy SDR when taking it to a Christmas theatre show. In a modern theatre show the actors and actresses typically wear hidden wireless microphones and earpieces, allowing their voices to be amplified and instructions from the producers and directors to be heard. If close enough, these devices can easily be picked up with a SDR and antenna.

In his video Rob explains what sort of radio devices and frequencies are used at the theatre, and despite a few set backs he manages to listen in on these devices from the lobby and from just outside the theatre complex. 

Some of the things he hears includes backstage instructions from the directors and production team and of course audio from the performers, including backstage conversations.

2021 SDR Guide Ep 12 : SDR Theatre fail with my AirSpy R2 and RTL-SDR dipole kit

Notify of

Inline Feedbacks
View all comments

Most recent/high-end wireless mic now implement encryption. For example Shure uses AES 256-bit encryption. So it will become more difficult to listen to microphones/intercoms around TV/movie sets, and big theaters, concert halls or entertainment parks… But smaller venues will probably not have budget to renew their non encrypted devices before a while, and probably don’t care about it.


They should make a demodulator for 8PSK wireless mics they mostly have to turn the encryption on


Just went down this path, for encryption, you would need to purchase the QLX line of Shure wireless microphones. They are very expensive ($1,000+ per Mic+Receiver Bundle) and encryption is disabled by default.